European Patent Publication No. EP 0219347B1 filed by ISHIDA SCALES MFG CO., LTD. with the filing date of 14 Oct. 1986 and the publication date of 14 Mar. 1990 discloses a weighing method and system, wherein a plurality of article batch handling units is controlled so that a high-speed dual or multiple packaging unit can be coupled and its capability can be utilized advantageously. For each cycle of the system operation, three or more combinations are selected by combinatorial computations on the weight values of article batches and they are discharged to the packaging unit through two discharge routes or more but fewer than the number of the selected combinations. This has the effect of discharging through each discharging route more than one per cycle.
Japanese Patent Publication No. JP8152353B2 filed by ISHIDA SEISAKUSHO with the filing date of 10 Apr. 1995 and the publication date of 11 Jun. 1996 discloses a method and apparatus for collecting material to be measured in combined measuring apparatus, wherein the collecting device is connected to a plurality of packaging machines, and at least three combinations are selected in each weighing cycle and the material is discharged through two or more discharging routes such that interactive packaging is realized. In this patent, the number of the discharging routes is also less than the number of combinations.
In the prior art as described in the above patents, each material treating unit includes a linear vibrator, a feed hopper and a weighing hopper. The weighing device uses the following connections: a weighing sensor is connected to an A/D converter which is connected to a processor, and the output result of the processor is sent to the mainboard to be computed. The weighing process of the weighing hopper in each weighing cycle is as follows: the weighing sensor is connected with weighing hoppers in the material treating unit one by one, that is, the weighing hoppers are weighed one by one until all the weighing hoppers are weighed, the weight of the materials in each weighing hopper is converted by the A/D converter and then sent to the mainboard to be computed. Furthermore, all the weighing hoppers are connected to one A/D converter, and thus the interchange is poor, and the weighing speed is not fast enough. Moreover, the number of the material discharging routes is less than the number of combinations, and the weighing hopper discharges the materials in three combinations through two discharging routes in turn. Compared with the traditional combination weighing device, the speed of material discharging is only increased by 1.5 times.